DC Universe Online biography

Bruce Wayne of Earth is one of several other-dimensional heroes that were captured by Brainiac during the villain's numerous trips through time and the Multiverse. Brainiac had traveled the Multiverse in search of unique heroes and villains from many worlds including alternate Earths to use as an army. Bat Lad was being used as a template for many of the new exobyte-enhanced humans until he was able to escape from a Brainiac ship with help from this Earth's Oracle and Superman. Upon escaping captivity, he sought out his friend Superboy, only to discover that he was on an alternate Earth and timeline from the one he had known. Batman (this world's version of Bruce Wayne - older and much more experienced) offered Bat Lad his aid and sponsored him as an honorary Justice League member seeking out his help in a series of adventures. Adjusting to his new life in this new time and this new Earth, Bruce has joined a new team of heroes known as Young Unity which features several of the exobyte-enhanced and other trans-dimensional heroes that Brainiac had kidnapped.

DC Comics biography

Alter Ego: Bruce Wayne
Other Alias: Batlad, Bat-Lad, Executioner
Known Relatives: Thomas Wayne (father, deceased), Martha Wayne (mother, deceased)
Homeworld: Earth
Height: 5' 10"
Weight: 170 lbs.
Eyes: Blue
Hair: Black
First Appearance: SUPERBOY #182 (February 1972)
Powers: Unlike most superheroes, he does not possess any superpowers; he makes use of intellect, detective skills, science and technology, wealth, physical prowess, martial arts skills, an indomitable will, fear, and intimidation in his continuous war on crime.
Origin/History: Superboy gave a young, angry Bruce Wayne a costume similar to the Batman design, but without the logo and the ears. Superboy knew the design thanks to his time telescope (or some similar gadget, I don't recall it's exact name). Superboy promptly tried to name the costumed Bruce "Batlad," but Bruce decided to initially go with another name, "Executioner."

SUPERBOY (Vol. 1) #182 (February 1972)

Bat Lad appears in "The Forging of Young Batman!," the first story written by Leo Dorfman, drawn by Bob Brown and Murphy Anderson. In this story, Superboy first learns of the murder of Thomas and Martha Wayne through an old headline and goes to see Bruce Wayne, who is capturing a burglar at the Wayne Mansion. Bruce is beginning his crime-fighting career as the masked and costumed Executioner, and has become convinced that his parents were killed by “The Zodiac Killer”, whose exploits are reported in the Gotham Gazette. But Superboy proves that the Zodiac Killer is merely a fiction dreamed up by sensationalist reporter Otis Higbee, and Bruce, embarrassed and angered, breaks up their partnership.